Compression bracket



April 1961 J. A. PEIIQRY, JR, BT51. 2,980,414

- COMPRESSION BRACKET Filed March 16, 1956 5 Sheets-Sheet 1 INVENTORS.

April 18, 1961 J. A. PERRY, JR., ETAL 2,980,414

COMPRESSION BRACKET Filed March 16, 1956 s Sheets-Sheet 2 Jja I I ,1 39M 0 a9 r ml 41 iv F INVENTORS.

{7 J1 rfosep/zal erryafn 115 II MZZZ'QIWM Haselzorz April 17961 J. A.PERRY, JR., ETAL 2,980,414

COMPRESSION BRACKET 3 Sheets-Sheet 3 Filed March 16, 1956 United StatesPatent 1 2,980,414 COMPRESSION BRACKET Joseph A. 'Perry, Jr., MortonGrove, Ill., and William M.

Haselton, Cedar Rapids, Iowa, assignors to Cherry- Burrell Corporation,Chicago, 111., a corporation of Delaware Filed Mar. 16, 1956, Ser. No.571,974 Claims. (Cl. 177-211) Our invention relates to a compressionbracket in which a suitable load-sensing device or cell may be mountedfor measuring weights or loads, and has reference more particularly to abracket type of device for isolating compressive force in a column fromconcurrent torsional, bending, or side-thrust forces and the like, so asto measure only the compressive force applied thereto.

The compression bracket embodying our invention is designed forinstallation in the supporting members or legs of platforms, conveyors,bulk material containers such as storage tanks and bins, and the like.The bracket is adapted to receive a force-measuring device or cell, suchas the unit described in Patent No. 2,709,790 to W. R. Swanson, issuedMay 31, 1955. The cell is interposed between opposed portions of thebracket. The bracket serves to transmit only compressive type forces tothe cell and to prevent transmission of moment type forces and the likethereto. The bracket will hereafter be disclosed in combination with theaforesaid type of force-measuring unit or cell, but it should beunderstood that other types of units, including those of the electronic,hydraulic, and pneumatic types, may be used with our compressionbracket.

It is the principal object of our invention to provide a compressionbracket which will communicate compressive force to a force-measuringunit and which will at the same time prevent communication to such unitof other type forces that may be applied to the compression bracket.

It is another object of our invention to devise such a compressionbracketwhich may be incorporated readily in the supports for storagetanks, bins, hoppers, weighing platforms, and the like at the time ofmanufacture, or which may be added conveniently to existinginstallations of such equipment.

It is a further object of our invention to design such a device which issimple in design, dependable in operation, and readily adaptable to awide variety of installations, these and other objects beingaccomplished as hereinafter described, reference being had to theaccompanying drawing in which:

Fig. 1 is a perspective view of a storage tank showing compressionbrackets installed inthe legs thereof;

Fig. 2 is a sectional view through a conveyor having a compressionbracket in a supporting member thereof;

Fig. 3 is a top view of the compression bracket embodying our inventionas taken on the line 3-3 of Fig. 2;.

Fig. 4 is a side view of compression bracket shown in Fig. 3;

Fig. 5 is a view on the line 55 of Fig. 4;

Fig. 6 is a diagrammatic side view of said bracket showing the effect ofcertain forces thereon;

Fig. 7 is a diagrammatic view of one of the other sides of said bracketshowing the effect of other forces thereon;

Fig. 8 is a side view of a modified form of compression bracket; and

Fig. 9 is a top view of bracket shown in Fig. 8.

Referring now to the drawing, the compression bracket of our inventionis designated generally by the reference :numeral 10 and is shown inFig. l as mounted between the upper parts 11a and lower parts 11b ofsupporting legs at the four corners of a storage tank 12. Each com-2,980,414 Patented Apr. 18, 1961 ice pression bracket 10 is providedwith a load sensing unit or cell 13, preferably of the type disclosed inPatent No.

2,709,790. The load cells 13 are connected in a suitable electricalcircuit through the cable 14 to an indicator 15. The compressive forceor weight exerted through the brackets 10 on the respective load cells13 is indicated cumulatively on the indicator 15 so that the totalweight in the storage tank 12 may be registered thereon. As explained inPatent No. 2,709,790, the indicator 15 may be adjusted in a manner toregister zero when the storage tank 12 is empty, thus permittingmeasurement of the weight of the contents when additional load isexerted on the load cells 13 and communicated through the cable '14 tothe indicator 15.

It will be understood that Where weight-sensing units of other typessuch as pneumatic or hydraulic are employed, the force or weight exertedthereon will be communicated in a suitable manner to similar indicators.

Another type of installation is shown in Fig. 2 wherein a conveyor beltor platform 16 moves between guides 17 mounted on a frame 18. The frame18 is mounted on a support similar to the legs on which the storage tank12 is mounted, comprising an upper leg part 11a and a lower leg part11b. A compression bracket 10 is interposed between the upper and lowerleg parts 11a and 11b, and a load cell 13 is provided therein. As theload shown on the belt or platform 16 in Fig. 2 passes over the frame18, the weight of the load exerts a compressive force through the upperleg part 11a and the bracket 10 on a load cell 13. In this type ofinstallation, where but a single load cell 13 is employed, the force orweight measured by the one load cell 13 would be communicated directlyto an indicator (not shown).

The bracket 10 has a top collar 19 which may be threadably or otherwiseengaged to the lower end of the upper leg part 11a. A correspondingbottom collar 20 is similarly engaged to the upper end of the lower legpart 11b. The top collar 19 is provided on its underside with an endwall 21 which may be welded or otherwise secured thereto. A hardenedblock or rocker plate 22 is mounted on the underside of the wall 21,said rocker plate 22 having a downwardly facing lengthwise V-groove 23.The bottom collar 20 has a similar end wall 24 with a rocker plate 22hearing against its upper side, with a V-groove 23 facing and alignedwith the corresponding V-groove 23.

Each of the rocker plates 22 is preferably formed with a slight convexcurvature on its back side as shown in Fig. 5 so as to permit a limitedend-to-end rocking movement as it bears against the respective end wall21 or 24. The rocker plates 22 are preferably notched at both ends ofthe V-groove 23 to receive the pegs 25 which are secured to the endwalls 21 and 24 to insure proper positioning of the rocker plates 22.

The load cell 13 as shown herein comprises a casing with load responsiveelements (not shown) enclosed therein. The casing of the load cell 13 isprovided on opposite faces with knife-edge bearing strips 26 which areadapted to exert measurable compressive pressure on the load responsiveelements within the casing. The opposed knife-edge bearing strips 26 areseated in the V-grooves 23 of the rocker plates 22. Thus, a load on theupper leg 11a is supported by the rocker plate 22 resting on the topknife-edge 26 of the load cell 13. Likewise, support is provided by thelower leg part 11b through the rocker plate 22 and the bottom knife-edge26 of the load cell 13 resting in the V-groove 23 of said rocker plate22. The load cell 13 is thus compressed between the two knife-edges 26when a load is imposed upon the upper leg part 11a.

The top collar 19 is provided with shoulders 27 and 28 extendingsomewhat tangentially in the same direction from opposite sides of thecollar 19, andeach shoulder I 27 and 28 is provided with a downwardlydepending arm or leg 29 and 30, respectively, said arms 29 and 30 beingsubstantially parallel. r

The bottom collar 20 has shoulders 31 and 32 and arms 33 and 34corresponding to those with which the top collar 19 is provided exceptthat the relative position is reversed. Thus the shoulders 31 and 32extend tangentially from the collar 20 in a direction opposite to thatof the shoulders 27 and 29. Likewise, the arms 33 and 34 are upwardlydepending from the shoulders 31 and 32, respectively, and aresubstantially parallel, as shown in Fig. 4.

Corresponding holes 35 are provided at the juncture of the shoulders 27and 28 with the arms 29 and 30, respectively, said holes being axiallyaligned. Likewise, axially aligned holes 36 are provided at thejunctures of the shoulders 31 and 32 with the arms 33 and 34,respectively.

The free ends of the arms 29 and 30, respectively, are provided withaxially aligned holes 37; and the free ends of the arms 33 and 34,respectively, are provided with axially aligned holes 38.

Axle members 39, which are of greater length than the distance betweenthe respective pairs of axially aligned holes 35, 36, 37, and 38,'aredisposed in said corresponding pairs of holes and protrude therebeyondat their respective ends. An upper stabilizer frame 40 of generallyrectangular form and with holes corresponding to and aligned with holes35 and 38 at each side of the bracket 16 is mounted on the respectiveends of the axle members 39 protruding through the holes 35 and 38. Acorre sponding lower stabilizer frame 41 of generally rectangular formis mounted below and in a plane substantially parallel with that of theupper stabilizer frame 40.. Lower stabilizer frame 41 has holescorresponding to and aligned with the holes 36 and 37 at each side ofthe bracket 13, and the respective holes thereof are engaged upon theends of the axle members 39 protruding through the holes 36 and 37. Inthis manner, the top collar 19 with its depending shoulders 27 and 23and arms 29 and 39 is linked together with the bottom collar 20 and itsdepending shoulders 31 and 32 and arms 33 and 34 by the axle members 39in a relatively square arrangement as shown in Fig. 4.

The ends of the axle members 39 are threaded to receive the nuts 42which serve to hold the bracket assembly together. The end portions ofthe axle members 39 engaged by the stabilizer frames 40 and 41 serve asbearings and permit free upward and downward movement of the top collar19 with respect to the bottom collar 20 and the stabilizer frames 40 and'41 serve to maintain a parallelogram relationship between the twocomponent parts of the bracket 10. Thus the V-groove 23 of the topcollar 19 remains parallel with the V-groove 23 of the bottom collar 20notwithstanding relative movement of said collars 19 and 20 toward andaway from each other.

It will be understood that when the load cell 13 is interposed betweenthe respective collars 19 and 20 with the knife-edges 26 seated in therespective V-grooves 23, the bracket lti permits vertical or compressiveforce to be applied to the load cell 13 without any restraining orinterfering influence.

The reaction of the bracket 16 to the application of various forces isillustrated in Figs. 6 and 7. In Fig. 6, the primary force to which thebracket is subjected is the compressive force indicated by the twoarrows C. At the same time, however, it is subjected to a secondaryforce, the bending momentindicated by the two arrows M. This may becaused by any of a number of factors such as angle of mounting, movementof load, or the like. It is to avoid communication of such secondaryforce to the load cell 13 that a bracket 19 is required. Since theefiect of the bending moment is to urge the upper pair of axles 39toward each other and the lower pair of axles 39 apart, it may be saidthat the secondary force is compressive on the upper stabilizer frame 40and tensile on the lower stabilizer frame 41. Since the two forces areresisted by said frames 40 and 41, respectively, no bending moment canbe communicated to the load cell 13. Thus as between compressive forceCC and the bending moment MM in Fig. 6, only the compressive force isexerted upon the load cell 13 and thus is the only force measuredthereby.

Fig. 7 shows the effect of a bending moment N-N applied to bracket 18 atright angles axially to the bending moment MM of Fig. 6. The bendingmoment N-N is resisted by the axle members 39 in combination with theupper and lower stabilizer frames 40 and 41 because of the engagement ofthe axle members 39 in the holes 35, 36, 37, and 38 of the shoulders 27and 28 and their depending arms 29 and 30 and the shoulders 31 and 32and their depending arms 33 and 34. Since this bracket assembly will notyield to the bending moment NN, that moment cannot be transmitted to theload cell 13 and the only force so transmitted is the compressive forceCC in the same manner as in Fig. 6.

Likewise, any other bending or torsional moments or force other thancompressive applied to the bracket 13. are resisted. Thus the bracket 10is incapable of transmitting such forces to the load cell 13. Moreover,as it evident from the'design of bracket 10, it is incapable ofsupporting any compressive load. Therefore, it is only by virtue of theinterposition of the load cell 13 that the upper portion of the bracket10 is supported with respect to the lower portion. As a result, the loadcell 13 receives the total compressive force exerted upon the bracket 10and receives none of the other forces or moments which may be appliedthereto.

Referring now to Figs. 8 and 9, the modified form of compression bracketshown therein employs the same principles as those employed with respectto the heretofore described bracket 10, but the bracket of Figs. 8 and 9is adapted to measure extremely heavy loads with a load cell 13 capableof bearing only a fraction of such loads.

As shown in Fig. 8, the bracket comprises a top collar 43 and a bottomcollar 44. End walls 45 and 46 are provided in the top collar 43 and thebottom collar 44, respectively. The top collar is provided at oppositesides. with a pair of corresponding offset downwardly depending arms orlegs 47 and the bottom collar 44 isprovided with a similar pair ofoffset upwardly depending arms or legs 48. Corresponding aligned holes49 are provided in the legs 47 adjacent the top collar 43 and similarlyaligned holes 50 are provided at the lower ends of said legs. Likewise,corresponding aligned holes 51 are provided in each of the legs 48adjacent the bottom collar 44 and similarly aligned holes 52 in the freeupper ends of said legs 48. Axle members 53 of greater length than thedistance between said pairs of holes 49, 50, 51, and 52 are engagedtherein and protrude outwardly therefrom at each side of the legs 47 and48. An upper rectangular stabilizer frame 54 is provided with holescorresponding to and aligned with the holes 49 and 52 in the legs 47 and48, said holes in the stabilizer frame 54 being engaged upon theprotruding ends of the axle members 53. Likewise, a lower rectangularstabilizer frame 55 is provided with holes corresponding to and alignedwith said holes 50 and 51 and the holes of said stabilizer frame 55 areengaged upon the outwardly protruding ends of the axle members 53engaged in the holes 50 and 51. The bracket of Figs. 8 and 9 is thussimilar in general construction to the bracket 10 heretofore described.

The end wall 46 of the bottom collar 44 is provided on its upper facewith a rocker plate 56, the back side of which is convexly curved asheretofore described in connection with rocker plates 22. The rockerplate 56 has an upwardly disposed knife-edge 57 which extends at rightangles on said rocker plate 56 to the axis of the curvature of the backside thereof. The knife-edge 57 serves as a fulcrum to support an arm58. The stub end 59 of said arm 58 is provided with transverse V-grooves 60 and 61. The elongated end 62 of the arm 58 is providedadjacent its tip with a transverse V- groove 63.

The end Wall 45 of the top collar 43 is provided at one side with aninner V-groove 64 and an outer V-groove 65 facing and aligned with thecorresponding V-grooves 60 and 61 on the stub end 59 of the arm 58. Theend wall 45 has a projection 66 at the side opposite to the location ofthe V-grooves 64 and 65 aligned and substantially coextensive with theelongated end 62 of the arm 58. The projection 66 is provided adjacentits tip with a down wardly facing rocker plate 67 with a lengthwisegroove 68 on its face, the back side of said rocker plate 67 beingcurved as heretofore described in connection with the rocker plates 22.

A load cell 13 is interposed between the V-groove 63 near the tip of theelongated end 62 of the arm 58 and the rocker plate 67 near the end ofthe projection 66. The arm is provided with a transverse groove 69between the elongated end 62 and the stub end 59, said groove beingengaged upon the knife-edge 57 which serves as a fulcrum. A double edgeknife bar is interposable between facing V-grooves 60 and 64 or 61 and65. As shown in Fig. 8, said knife bar 70 is seated at its respectivesides in the V-grooves 60 and 64.

Thus when a load is imposed upon the top collar 43 the greatestproportion of the load is carried by the knife bar 70 resting on thestub end 59 of the arm 58, the load being exerted therefrom through therocker plate 56 to the bottom collar 44. A predetermined fraction of theload is transmitted through the projection 66 to the load cell 13 andthereby to the elongated end 62 of the arm 58. As will be understood,the exact positioning of the knife bar 70 with respect to the axis ofthe top and bottom collars 43 and 44 and the spacing of the load cell 13at the opposite side of said axis determines what proportion of the loadis exerted through the load cell 13. In the form illustrated in Fig. 8,the load cell 13 carries 20 percent of the load when the knife bar 70 isseated in the inner V-grooves 60 and 64 and carries 25 percent of theload when said knife bar 70 is seated in the outer V-grooves 61 and 65.

As heretofore described, the load cell of Figs. 8 and 9 would beconnected by suitable cable (not shown) to an indicator (not shown)which would be adjusted to register the total load by virtue of thefraction of the load communicated to it from the load cell 13.

While we have shown and described our invention in preferred forms, itwill be understood that various modifications and changes can be made inthe specific features thereof and in the general assembly as well as inthe type of load cell or load measuring unit employed therewith withoutdeparting from the spirit of our invention, the scope of which is to bedetermined by the appended claims.

We claim:

1. A bracket of the class described comprising the combination of anupper block and a lower block having portions disposed in face-to-facespaced apart relation to receive a load-sensitive cell therebetween,each of said blocks having two corresponding spaced apart leg membersprojecting toward one side of the other block in relatively straddlingrelation, each block being provided with a. substantially rectangularframe pivotally mounted on the leg members thereof adjacent the block ina plane substantially perpendicular to that of said leg members, saidframe also being pivotally connected to the free ends of the legs of theother block.

2. A bracket of the class described comprising the combination of anupper block and a lower block having portions disposed in face-to-facespaced apart relation to receive a load-sensitive cell therebetween,each of said blocks having two corresponding spaced apart leg membersprojecting toward one side of the other block in relatively straddlingrelation, each block being provided with a substantially rectangularframe pivotally mounted on the leg members thereof adjacent the block ina plane substantially perpendicular to that of said leg members, saidframe also being pivotally connected to the free ends of the legs of theother block, each block being provided with means for engagement with asupporting member of a device to be weighed.

3. A compression bracket for a force measuring device mounted betweentwo relatively movable aligned members to which force is applied, saidbracket comprising independent connecting means for securing saidbracket to each of said relatively movable members, said means includingportions disposed in face-to-face spaced-apart relation to receive theforce measuring device therebetween, each of said means having a pair ofarms extending substantially in the direction of the force to bemeasured and oppositely to the arms of the other means, andsubstantially rectangular frames pivotally connected to one pair of armsadjacent their connecting means and to the other pair of arms at theirfree ends, said frames being disposed parallel to each other andperpendicular to said arms thereby forming a parallelogramrnaticstructure.

4. A compression bracket for a force measuring device mounted betweentwo relatively movable members to which force is applied, said bracketcomprising a support means secured to each of said members, each of saidsup port means having a shoulder, said shoulders being disposed inspaced-apart relation to receive the force measuring devicetherebetween, an arm extending from each of said shoulders along a linesubstantially parallel to the applied force, the arm of one supportmeans extending oppsitely to the arm of the other support means, andmeans interconnecting said support means by pivotal connection with thearm of one support means and the shoulder of the other support means,said last mentioned means and said arms forming a parallelogrammaticstructure, the sides of which are pivotally interconnected.

5. A compression bracket for a force measuring device mounted betweentwo relatively movable aligned members to which compressive force isapplied, said bracket comprising independent connecting means forsecuring said bracket to each of said relatively movable members, saidmeans including portions disposed in face-to-face spaced-apart relationto receive the force measuring device therebetween, each of said meanshaving an arm extending substantially in the direction of the force tobe measured and oppositely to the arm of the other means, andsubstantially rectangular frames each connected to one arm adjacent itsconnecting means and to the other arm at its free end, said frames beingdisposed parallel to each other and perpendicular to said arms therebyforming a parallelogrammatic structure.

References Cited in the file of this patent UNITED STATES PATENTS308,440 Smith Nov. 25, 1884 2,090,188 Dahlstrom Aug. 17, 1937 2,411,023Bruns Nov. 12, 1946 2,634,966 Williams Apr. 14, 1953 2,659,592 WetselNov. 17, 1953 2,666,262 Ruge Jan. 19, 1954 2,670,195 Baker Feb. 23, 19542,767,974 Ballard et al. Oct. 23, 1956 2,802,660 Williams Aug. 13, 19572,805,055 Swanson Sept. 3, 1957 2,812,935 Mettler Nov. 12, 19572,822,095 Buckingham Feb. 4, 1958 FOREIGN PATENTS 301,121 Great BritainNov. 29, 1928 427,347 Great Britain Apr. 23, 1935 761,259 Great BritainNov. 14, 1956

